With development of technology, liquid crystal display (LCD) screens can be seen to be used for various applications everywhere, such as liquid crystal display televisions, mobile phones, medical displays and so on. Materials of the liquid crystal display screens are generally glasses, which are easily broken. In addition, the quantity of pixels is too large and each pixel is very small, therefore the phenomenon of individual pixel breakdown often occurs, which is known as a malfunctioned pixel, and the malfunctioned pixel is usually difficult to repair. If the malfunctioned pixel exceeds a certain standard, the entire display screen should be replaced. In some applications, the price of the replacement of one LCD screen is generally very expensive. In order to prevent LCD screens from being damaged, the LCD screens employed in the medical field, such as the medical displays, and the displays used in monitor display systems are generally provided with protective plates that are used for the LCD screens.